Rewriting queries using views over monadic database schemas

被引：0

作者：

Van den Bussche, J ^{[1
]}

机构：

[1] Univ Limburg, Dept WNI, B-3590 Diepenbeek, Belgium

来源：

INFORMATION PROCESSING LETTERS | 2001年 / 79卷 / 03期

关键词：

algorithms; computational complexity; databases;

D O I：

10.1016/S0020-0190(00)00180-0

中图分类号：

TP [自动化技术、计算机技术];

学科分类号：

0812 ;

摘要：

The equivalent rewriting variant of the problem of rewriting queries using views requires of a rewriting not only that its expansion is contained in Q, but that it is actually equivalent to Q. If an equivalent rewriting exists, it is clearly also an optimal contained rewriting, and conversely, every optimal contained rewriting will in fact be an equivalent rewriting. Hence, the algorithms for finding an optimal contained rewriting can be used to find an equivalent rewriting as well. It suffices to check at the end that Q is contained in the expansion of the found rewriting. This check can be implemented in polynomial time over monadic schemas.

引用

页码：111 / 114

页数：4